Sorry, I guess I did not make it clear: I never closed my account. I just stopped using it. Also, all I used on the HDFC website is something called QuickRemit which is just a means to wire money directly from my US bank account to an established beneficiary in India (who is required to have a regular HDFC checking/savings account in India - in this case, my dad).
@ginnu: In your friend's case, how did the HDFC people even know that he was no longer an Indian citizen (assuming that he had opened his account when he was an NRI)?
---------------HDFC bank did not know that he got US citizenship. He informed the bank. his account was not Active. HDFC sent form attached in his email that he submitted to HDFC to Activate the account and He also sent the US passport Copy+OCI copy.
***ICICI bank NRE account also becomes inactive if no transaction in 12 or 15 months and one need to send the Form to Activate the account. ICICI has better service as you can call them on toll free number and can ask the question or information but HDFC has no number to call them directly.